What is the density of stainless steel 304?

Grade 304 (the most common austenitic stainless) has a density of 7930 kg/m³ (0.286 lb/in³). This is slightly higher than carbon steel (7850 kg/m³) due to the chromium and nickel alloying elements.

How is the flat bar weight calculated?

The formula is: Weight = Width × Thickness × Length × Density. All dimensions are converted to meters first, giving a volume in m³. Multiplying by the grade density (kg/m³) gives the weight in kilograms.

What is the difference in weight between 304 and 316?

Grade 316 has a density of 8000 kg/m³ vs 7930 kg/m³ for 304, a difference of about 0.9%. For most practical calculations this is negligible, but this calculator uses the correct per-grade density for accuracy.

Why is 2205 duplex lighter than 304?

Duplex 2205 has a density of about 7805 kg/m³, slightly lower than austenitic grades. Despite being lighter, it offers roughly twice the yield strength of 304, making it highly efficient for structural use.

Can I calculate weight for multiple bars?

Yes. Set the Quantity field to the number of bars and the calculator multiplies the per-bar weight by that number, showing both the total weight and the individual bar weight.

Does this work with imperial units?

Yes. You can enter width and thickness in inches and length in feet or inches. The calculator converts all values to meters internally before applying the density formula.

How accurate are the results?

Results are theoretical weights based on nominal dimensions and standard grade densities per ASTM and EN specifications. Actual weights may vary slightly due to manufacturing tolerances (typically ±3–5%).

Stainless Steel Flat Bar Weight Calculator

Enter width, thickness, and length, pick a stainless steel grade, and get the exact weight in kg and lbs instantly.

Bar Dimensions

Width

Thickness

Length

Stainless Steel Grade

Quantity (bars)

Formula Reference

Weight (kg) = W (m) × T (m) × L (m) × ρ (kg/m³)

W = width, T = thickness, L = length, ρ = grade density. All dimensions must be in meters before applying.

Enter dimensions on the left and click Calculate.

Stainless Steel Grade Densities

Grade	Type	kg/m³	lb/in³
304 / 304L	Austenitic	7930	0.286
316	Austenitic	8000	0.289
316L	Austenitic (LC)	7980	0.288
321	Ti-stabilized	7900	0.285
430	Ferritic	7700	0.278
410	Martensitic	7650	0.276
2205 Duplex	Duplex	7805	0.282
2507 S. Duplex	Super Duplex	7800	0.282

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Summary

This calculator computes the weight of a stainless steel flat bar using the formula: Weight = Width × Thickness × Length × Grade Density. Each stainless steel grade has its own certified density — for example, 304 is 7930 kg/m³ and duplex 2205 is 7805 kg/m³. Results are shown in kilograms and pounds. Supports metric and imperial dimension inputs and a quantity multiplier for batch orders.

How it works

Enter the flat bar width in your preferred unit (mm, cm, or inches).
Enter the flat bar thickness in the same or a different unit.
Enter the bar length in meters, millimeters, feet, or inches.
Select the stainless steel grade — the correct density is applied automatically.
Optionally set a quantity to calculate the total weight for multiple bars.
Click Calculate Weight to see results in kg and lbs with a full dimensional breakdown.

Use cases

Estimating stainless steel material weight for fabrication and procurement.
Calculating freight and shipping costs for flat bar stock orders.
Verifying weight specs against supplier certificates for quality assurance.
Comparing grade choices (e.g., 304 vs 316) by weight difference.
Preparing bills of materials (BOM) for food-grade or marine equipment.
Checking load capacity for stainless steel structural members.
Generating quick weight estimates for architectural and cladding projects.

Frequently Asked Questions

Last updated: 2026-05-23 · Reviewed by Nham Vu